Dowel bar installing device



May 13, 1952 F. D. CARNES DOWEL BAR INSTALLING DEVICE Filed Aug. 22, 1949 m 3 m B k V N. T N R T I A-A W m H & m N

Patented May 13, 1952 DOWEL BAR INSTALLING DEVICE Fred D. Carncs, Fort Worth, Tex., assignor to Flexible Road Joint Machine Company, Warren, Ohio, a corporation of Ohio Application August 22, 1949, Serial No. 111,631

4 Claims. 1

The present invention relates to improvements in dowel bar installing devices, and more particularly relates to an improved plunger for use on an existing form of dowel bar-and tie-bar installing machine.

In existing machines the dowel and tie-bars are held to the lower cut-away ends of the plungers by means of curved pivoted fingers which are connected for operation to reciprocating bars on the machine whereby these .fingers may be withdrawn as the dowel bars andplungers are caused to penetrate the plastic concrete of a road under construction.

The present invention aims to dispense with the use of the fingers and the operating mechanism for the fingers and to this'extentto simplify the construction of dowel and tie-bar installing devices together with the expense of the construction of such eliminated parts and the time and labor involved in the operation of the same.

It is another object of the invention to provide an exceedingly simple form of plunger so constructed and arranged at its lower end as to n constitute a recessed supporting ledge at one side of the plunger for supporting the dowel or tiebars when .the plunger is elevated above the concrete mass; the lower end portion of the plunger being further so constructed and arranged as to provide a diagonal or inclined surface for guiding the dowel or tie-bar out of the recessed supporting ledge and out of line therewith incident to the movement of the dowel or tie-bar into the plastic concrete mass by the downward motion of the plunger, whereby the dowel or tie-"bar when positioned at the proper depth in the concrete will have been automatically moved out of the path of the recessed or supporting ledge to the end that the plunger may be lifted from the concrete without disturbing the set position or" the dowel or tie-bar.

The invention further contemplates the formation in the lower end of the improved plunger of an inverted hook shaped upper surface at the upper end of the inclined or diagonal wall to arrest the relative upward movement of the dowel bar with respect to the plunger and which will trap the dowel or tie bar in this hook shaped upper surface to insure that the full downward thrust of the plunger shall be communicated to the dowel bar to force the same downwardly into the plastic concrete to the desired depth.

It is the further purpose of the present invention to achieve the above objects without in any way introducing changes that require any re construction of the present machine.

With the foregoing and other objects in view, the invention will be more fully described hereinafter, and will be more particularly pointed out in the claims appended hereto.

In the drawings, wherein like symbols refer to like or corresponding parts throughout the several views,

Figure 1 is a fragmentary perspective view .of a conventional form of dowel bar and tie-bar installing machine illustrating the improved plungers according to the present invention.

Figure 2 is a fragmentary front elevational view of a plunger seam with one of the improved plungcrs applied thereto and taken on an eniarged scale with a dowel or tie-bar in the plunger supported on the ledge of the plunger at an elevation above the plastic concrete.

Figure 3 is a fragmentary front elevational view or" the same plunger shown as partially entered into the plastic concrete with the dowel or tie-bar riding upwardly on the diagonal or inclined wall.

Figure 4 is a similar view showing the plunger pushed down to a greater extent into the plastic mass and with the dowel or tie-bar engaged in the hook shaped upper surface.

Figure 5 is a similar view showing the "plunger as withdrawn upwardly and the dowel or tie-bar remaining in the plastic concrete.

Figure 6 is a vertical sectional view taken on the line 6-45 in Figure 2.

Figure 7 is an end fragmei itary elevational View of the plunger taken on the lines l! in Figure 2.

Referring more particularly to the drawings 10 and H represent beams or supports extending both longitudinally and horizontally on the dowel bar installing machine designated generally at E2 which supports are provided with series of perforations l3 for receiving bolts, screws or other fastenings H whereby the plunger or inserter hars may be adjustably attached to the supports.

Dowel bars is are shown as held in certain of the supports and tie-bars I! in the other supports. Vibrators l8 and I9 aremounted upon the supports for communicating vibratory movement to the supports, plungers and dowel and tie-bars as the same are moved down into the plastic concrete indicated at 20.

A hydraulic lifter 2| is mounted on the machine and connected in the usual way to lift the supports id and the plungers or inserter bars 15 after the dowel and tie-bars have been installed in the plastic concrete 2!].

The holes I3 provide for various specifications regarding dowel and tie-bar spacings. The machine also carries a transverse joint cutter 22.

In accordance with the present invention the lower end of each plunger or inserter bar is notched from its side edge to provide a dowel receiving pocket having a recessed supporting ledge 23 which is made to one side of the vertical center line of the plunger l5 and which is open at the side adjacent such center line but 3 closed at the opposite side as indicated at 24. At the open side the lower or bottom curved wall of the supporting ledge 23 will have an upwardly extending lip 25 formed in continuation of the circle on which the ledge 23' is struck which circle will conform generally to the curvature of the dowel or tie-bar. Below the center portion of the ledge 23 the lowermost end of the plunger is pointed as indicated at 26 to facilitate its penetration downwardly into the concrete 28. Above the ledge 23 is a diagonal or inclined wall 21 which merges at its lower outer end portion into the curved portion of the closed side wall 24 of the ledge 23. The upper end of this diagonal or sloping wall 21 leads to an inverted hook shaped upper surface 28.

Thi upper surface 28 is a complement of the ledge 23 and is offset to the opposite side of the center line of the plunger I5. In other words with reference to the diameter of the dowel and tie bars II, when the latter occupy the inverted hook shaped upper surface 28 they will clear the ledges 23 and the upstanding lips 25 thereof.

The inner side of the upper surface 28 connectsv with the inclined or diagonal wall 21 and the outer side of the upper surface 28 is provided with a downwardly projecting lip 29 to confine the dowel and tie-bars in place. The upper surface 28 may be curved to conform to the curvature of the dowel and tie-bars.

In the use of the device, with the plungers l5 in initial position supported Wholly above the plastic concrete 28 which has just been recently deposited on the sub-grade between the side forms and screeded into place, the tie-bars I! and dowels 16 are simply slipped into the pockets of adjacent alined plungers I5, as shown in Figure 1, whereby the end portions of these dowel and tiebars are supported on the ledges 23 in the manner shown in Figure 1 and in Figures 2 and 6.

The supports Ill and II are then permitted to descend, the vibrators l8 and [9 being put into operation. Initially the lead-in points 26 at the lower ends of the plungers will enter the concrete 28. As the plungers or inserter bars l5 move down in the newly-laid concrete, the bars I6, I! encounter the resistance of the concrete and therefore, as shown in Figure 3, the plungers I15 will move down relatively to the bars ll inas much as the bars are free to escape through the r upper and inner open portions of the ledges and the diagonal or inclined walls 21 will ride downwardly on the bars I! which are slowed by the heavy concrete mass 20. This action will continue until the position of Figure 4 is arrived at. In other words the bars I! will be forced into the inverted hook shaped upper surfaces 28 where they will be trapped by the downwardly extending lips 29 and required to then move down with the plungers I5 into the concrete to the desired depth, for instance shown in Figure 5. When the rods I! arrive at the desired depth the hydraulic lifter 2| is operated to raise the supports l0 and I I and the plungers l5. As shown in Figure 5 the raising of the plungers will leave the bars H in the concrete inasmuch as the con- 4 crete will hold the rods I! in position while the plungers are raised, it being understood that the ledges 23, being offset from the upper surfaces 28 do not interfere with the withdrawal of the plungers upwardly from the concrete.

As shown in Figures 2, 3, 4, 5, 6 and 7 the pointed end 26 is beveled to constitute a cutting edge on the dowel plungers.

As shown more particularly in Figure '7 the lip 29 is also tapered in edge aspect besides being pointed in elevational aspect to also provide cutting edges to facilitate the penetration of the concrete.

It is obvious that various changes and modifications may be made in the details of construction and design of the above specifically described embodiment of this invention without departing from the spirit thereof, such changes and modifications being restricted only by the scope of the following claims.

What is claimed is:

1. A dowel bar installing device comprising a plunger, a dowel receiving pocket notched from the side edge of said plunger, said pocket having a recessed supporting ledge, an inverted hook shaped upper surface above said ledge and outwardly ofiset therefrom, and in inclined wall therebetween. V

2. A dowel bar installing device comprising a plunger, a dowel receiving pocket notched from the side edge of said plunger, adjacent its lower portion, said pocket having a supporting ledge open through the side notched portion, said ledge having a free edge with an upstanding lip therefon, an inverted hook shaped upper surface above said ledge and outwardly offset therefrom, and an inclined wall between said ledge and hook shaped upper surface.

3. A dowel bar installing device comprising a plunger, a dowel receiving pocket notched from the side edge of said plunger, said pocket having a recessed supporting ledge, an upper dowel bar receiving surface above said ledge and outwardly offset therefrom, an inclined wall connecting the inner portions of said ledge and upper surface and a downwardly projecting lip on the outer portion of said upper surface.

4. A dowel bar installing device comprising a plunger, a dowel receiving pocket notched from the side edge of said plunger, said pocket having a recessed supporting ledge, an inverted hook shaped upper surface above said ledge and outwardly offset therefrom, an inclined wall between said ledge and upper surface, and a pointed lower end below said ledge.

FRED D. CARNES.

REFERENCES CITED The following references are of recordin the file of this patent:

UNITED STATES PATENTS Number 

